"Mega Millions had been outshined somewhat by the massive jackpots of the Powerball game, which doubled ticket prices to $2 in January 2012, enriching jackpots as it also added a number of secondary prizes.

"Mega Millions received a makeover of its own in October specifically to increase the size of jackpots. The biggest change was lowering the odds of winning, which led to fewer winners and more rollovers.

"This jackpot has been growing since Oct. 1 and now has rolled over 21 times without a winner."